39. Sales & Customer Process

Learning objectives

Run the lead-to-close process honestly.
Qualify sites and build accurate proposals.

Lead → qualification → site assessment → proposal → close → handoff to operations. Qualification screens for roof suitability, shading (Ch 18), service adequacy (Ch 16.4), creditworthiness for financing, and genuine motivation. The proposal presents an honest production estimate (modeled in PVWatts/SAM, Ch 19), projected savings, financing options, and payback.

39.2 Ethics

Derate: a multiplier (less than 1.0) applied to rated module output to account for real-world losses such as wiring resistance, soiling, mismatch, and inverter efficiency. A conservative (realistic) derate produces a lower, more honest production estimate.

P50: the median production estimate: the output level exceeded in roughly half of years. Proposals should use P50 as the customer-facing number; P90 (exceeded 90% of years, so a lower figure) is reserved for lender underwriting.

TPO (Third-Party Ownership): a financing structure where a company (not the homeowner) owns the solar system and sells the electricity or leases the equipment to the customer, typically as a lease or power purchase agreement (PPA).

OBBBA (One Big Beautiful Bill Act): federal legislation that eliminated the residential solar tax credit (Section 25D) for new homeowner-owned systems, shifting the sales narrative toward utility-rate avoidance and TPO structures.

The defining temptation in solar sales is the inflated production or savings estimate. A proposal that quietly assumes an unrealistic derate, ignores shading, or omits degradation closes more deals and creates more disappointed customers, callbacks, and reputational damage. ⚠️ Model to P50 honestly (Ch 19); transparent contracts and realistic numbers are both ethical and, long-term, better business. Post-OBBBA, residential selling increasingly leads with utility-rate avoidance and TPO structures rather than a now-defunct homeowner tax credit.

39.3 The sales-to-operations flow

 LEAD ─► QUALIFY ─► SITE ASSESS ─► PROPOSAL ─► CLOSE ─► HANDOFF to ops
         (roof,      (measure,      (modeled    (sign)   (survey→design→
          shade,      verify         production,           permit→install)
          service,    Ch 30)         savings,
          credit,                    financing,
          motivation)                payback)
                                        │
                                    ⚠️ model to P50 honestly (Ch 19)

Chapter 39 summary

Move leads through qualification, assessment, proposal, and close, then hand to operations. Qualify honestly and build proposals on realistic modeled production. Inflated estimates are the industry’s besetting ethical failure. Sell on rate-avoidance and (residentially) TPO in the post-25D era.

Derate: a multiplier below 1.0 that translates rated module output to real-world production by accounting for wiring, soiling, mismatch, and inverter losses.
P50: median annual production estimate; the number used in customer-facing proposals.
TPO (Third-Party Ownership): lease or PPA structure where a company owns the system and the customer buys the power or rents the equipment.
OBBBA: legislation that ended the homeowner solar tax credit (25D), shifting residential sales toward rate-avoidance and TPO.
Qualification: the pre-proposal screen covering roof suitability, shading, service adequacy, creditworthiness, and motivation.

Full definitions: Appendix A (glossary).

Practice Problems: Chapter 39

List the stages of the sales process from lead to handoff.
What four things does qualification typically screen for?
What production figure (P50 or P90) should a residential proposal be built on, and why?
In the post-25D market, what should residential sales lead with instead of the homeowner tax credit?
What is the industry’s “besetting ethical failure” in sales, per this chapter?

Solutions: Chapter 39

Lead → qualification → site assessment → proposal → close → handoff to operations.
Roof suitability, shading, service adequacy, and creditworthiness/motivation.
P50 (the median expected value): honest expected production; P90 is for lender underwriting, not customer expectation-setting.
Utility-rate avoidance and third-party ownership (lease/PPA) structures.
Inflated production/savings estimates that close deals but disappoint customers.

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